From 8acfad38ca7b8b95f8e419ab47f69057b49bec91 Mon Sep 17 00:00:00 2001 From: Niall Date: Thu, 21 Nov 2019 12:15:44 +0000 Subject: doh: use dedicated probe slots ... to easier allow additional DNS transactions. Closes #4629 --- lib/doh.c | 84 +++++++++++++++++++++++++++++++---------------------------- lib/urldata.h | 20 +++++++++++++- 2 files changed, 63 insertions(+), 41 deletions(-) diff --git a/lib/doh.c b/lib/doh.c index 73ccce95e..1588a7f32 100644 --- a/lib/doh.c +++ b/lib/doh.c @@ -385,6 +385,7 @@ Curl_addrinfo *Curl_doh(struct connectdata *conn, { struct Curl_easy *data = conn->data; CURLcode result = CURLE_OK; + int slot; *waitp = TRUE; /* this never returns synchronously */ (void)conn; (void)hostname; @@ -403,8 +404,8 @@ Curl_addrinfo *Curl_doh(struct connectdata *conn, if(conn->ip_version != CURL_IPRESOLVE_V6) { /* create IPv4 DOH request */ - result = dohprobe(data, &data->req.doh.probe[0], DNS_TYPE_A, - hostname, data->set.str[STRING_DOH], + result = dohprobe(data, &data->req.doh.probe[DOH_PROBE_SLOT_IPADDR_V4], + DNS_TYPE_A, hostname, data->set.str[STRING_DOH], data->multi, data->req.doh.headers); if(result) goto error; @@ -413,8 +414,8 @@ Curl_addrinfo *Curl_doh(struct connectdata *conn, if(conn->ip_version != CURL_IPRESOLVE_V4) { /* create IPv6 DOH request */ - result = dohprobe(data, &data->req.doh.probe[1], DNS_TYPE_AAAA, - hostname, data->set.str[STRING_DOH], + result = dohprobe(data, &data->req.doh.probe[DOH_PROBE_SLOT_IPADDR_V6], + DNS_TYPE_AAAA, hostname, data->set.str[STRING_DOH], data->multi, data->req.doh.headers); if(result) goto error; @@ -425,8 +426,9 @@ Curl_addrinfo *Curl_doh(struct connectdata *conn, error: curl_slist_free_all(data->req.doh.headers); data->req.doh.headers = NULL; - Curl_close(&data->req.doh.probe[0].easy); - Curl_close(&data->req.doh.probe[1].easy); + for(slot = 0; slot < DOH_PROBE_SLOTS; slot++) { + Curl_close(&data->req.doh.probe[slot].easy); + } return NULL; } @@ -937,46 +939,43 @@ UNITTEST void de_cleanup(struct dohentry *d) CURLcode Curl_doh_is_resolved(struct connectdata *conn, struct Curl_dns_entry **dnsp) { + CURLcode result; struct Curl_easy *data = conn->data; *dnsp = NULL; /* defaults to no response */ - if(!data->req.doh.probe[0].easy && !data->req.doh.probe[1].easy) { + if(!data->req.doh.probe[DOH_PROBE_SLOT_IPADDR_V4].easy && + !data->req.doh.probe[DOH_PROBE_SLOT_IPADDR_V6].easy) { failf(data, "Could not DOH-resolve: %s", conn->async.hostname); return conn->bits.proxy?CURLE_COULDNT_RESOLVE_PROXY: CURLE_COULDNT_RESOLVE_HOST; } else if(!data->req.doh.pending) { - DOHcode rc; - DOHcode rc2; + DOHcode rc[DOH_PROBE_SLOTS]; struct dohentry de; + int slot; /* remove DOH handles from multi handle and close them */ - curl_multi_remove_handle(data->multi, data->req.doh.probe[0].easy); - Curl_close(&data->req.doh.probe[0].easy); - curl_multi_remove_handle(data->multi, data->req.doh.probe[1].easy); - Curl_close(&data->req.doh.probe[1].easy); + for(slot = 0; slot < DOH_PROBE_SLOTS; slot++) { + curl_multi_remove_handle(data->multi, data->req.doh.probe[slot].easy); + Curl_close(&data->req.doh.probe[slot].easy); + } /* parse the responses, create the struct and return it! */ init_dohentry(&de); - rc = doh_decode(data->req.doh.probe[0].serverdoh.memory, - data->req.doh.probe[0].serverdoh.size, - data->req.doh.probe[0].dnstype, - &de); - Curl_safefree(data->req.doh.probe[0].serverdoh.memory); - if(rc) { - infof(data, "DOH: %s type %s for %s\n", doh_strerror(rc), - type2name(data->req.doh.probe[0].dnstype), - data->req.doh.host); - } - rc2 = doh_decode(data->req.doh.probe[1].serverdoh.memory, - data->req.doh.probe[1].serverdoh.size, - data->req.doh.probe[1].dnstype, - &de); - Curl_safefree(data->req.doh.probe[1].serverdoh.memory); - if(rc2) { - infof(data, "DOH: %s type %s for %s\n", doh_strerror(rc2), - type2name(data->req.doh.probe[1].dnstype), - data->req.doh.host); - } - if(!rc || !rc2) { + for(slot = 0; slot < DOH_PROBE_SLOTS; slot++) { + rc[slot] = doh_decode(data->req.doh.probe[slot].serverdoh.memory, + data->req.doh.probe[slot].serverdoh.size, + data->req.doh.probe[slot].dnstype, + &de); + Curl_safefree(data->req.doh.probe[slot].serverdoh.memory); + if(rc[slot]) { + infof(data, "DOH: %s type %s for %s\n", doh_strerror(rc[slot]), + type2name(data->req.doh.probe[slot].dnstype), + data->req.doh.host); + } + } /* next slot */ + + result = CURLE_COULDNT_RESOLVE_HOST; /* until we know better */ + if(!rc[DOH_PROBE_SLOT_IPADDR_V4] || !rc[DOH_PROBE_SLOT_IPADDR_V6]) { + /* we have an address, of one kind or other */ struct Curl_dns_entry *dns; struct Curl_addrinfo *ai; @@ -998,21 +997,26 @@ CURLcode Curl_doh_is_resolved(struct connectdata *conn, if(data->share) Curl_share_unlock(data, CURL_LOCK_DATA_DNS); - de_cleanup(&de); - if(!dns) + if(!dns) { /* returned failure, bail out nicely */ Curl_freeaddrinfo(ai); + } else { conn->async.dns = dns; *dnsp = dns; - return CURLE_OK; + result = CURLE_OK; /* address resolution OK */ } - } + } /* address processing done */ + + /* Now process any build-specific attributes retrieved from DNS */ + + /* All done */ de_cleanup(&de); + return result; - return CURLE_COULDNT_RESOLVE_HOST; - } + } /* !data->req.doh.pending */ + /* else wait for pending DOH transactions to complete */ return CURLE_OK; } diff --git a/lib/urldata.h b/lib/urldata.h index da7e58f45..a70b2b09a 100644 --- a/lib/urldata.h +++ b/lib/urldata.h @@ -528,6 +528,24 @@ enum upgrade101 { UPGR101_WORKING /* talking upgraded protocol */ }; +enum doh_slots { + /* Explicit values for first two symbols so as to match hard-coded + * constants in existing code + */ + DOH_PROBE_SLOT_IPADDR_V4 = 0, /* make 'V4' stand out for readability */ + DOH_PROBE_SLOT_IPADDR_V6 = 1, /* 'V6' likewise */ + + /* Space here for (possibly build-specific) additional slot definitions */ + + /* for example */ + /* #ifdef WANT_DOH_FOOBAR_TXT */ + /* DOH_PROBE_SLOT_FOOBAR_TXT, */ + /* #endif */ + + /* AFTER all slot definitions, establish how many we have */ + DOH_PROBE_SLOTS +}; + struct dohresponse { unsigned char *memory; size_t size; @@ -544,7 +562,7 @@ struct dnsprobe { struct dohdata { struct curl_slist *headers; - struct dnsprobe probe[2]; + struct dnsprobe probe[DOH_PROBE_SLOTS]; unsigned int pending; /* still outstanding requests */ const char *host; int port; -- cgit v1.2.3